Disclaimer: I do not own Black Widow or anything to do with Marvel. I do not make any money from the writing of this story.

*****

“So, are you going to point a gun at me again?”

“That depends…”

“On what?”

“If you’re going to point one at me.”

Natasha Romanoff had detected someone inside her hideout almost immediately, and then smiled when she realized who it was. Her ‘sister’ Yelena Belova was normally better about covering her tracks, given that she was one of the best graduates of The Black Widow program. Which meant that she wanted Natasha to know she was there, and therefore was unlikely there to fight.

Something which was more or less confirmed with that little exchange. And even though it went against her training, she holstered her weapon and came out of the shadows. Which was breaking the rules, but it wouldn’t be the first time she had done that for her sister. Or the last.

It had been a long day… or more accurately, it had been a long life, with the last few years seeming particularly long. But seeing Yelena sitting on one of the chairs inside her safe house put her at ease, and almost forced a smile out of her. At least until she saw the little bitch was holding a glass of her favourite scotch, with a half empty bottle on the table in front of her.

Natasha had been planning to drink that herself when she got back, now it was practically gone. A fact which had Yelena smirking like the annoying little sister she was. Or at least, the role she had perfected. Certainly the safest way Natasha could look at her, the redhead wondered dismissively, before collapsing down on the couch beside the chair and taking the glass which was waiting for her.

“You could have saved me more than this.” Natasha grumbled, before taking a sip of the scotch.

“You’re always such a baby.” Yelena grumbled, although a smirk shone through again, “You have plenty left. And I even bought you some vodka. I can’t believe you didn’t have any vodka.”

“I do not enjoy leaning into stereotypes, as you do.” Natasha quipped light-heartedly.

“Is that why you got rid of your accent?” Yelena questioned with a raised eyebrow, her own Russian accent seeming particularly thick in that moment.

Natasha took another sip of her drink, and then pointed out, “We’re assassins. We’re supposed to be able to infiltrate, without giving ourselves away.”

“No, I’m an assassin.” Yelena countered bitterly. taking a sip of her own drink, “You? You’re an Avenger. The World’s Greatest Heroes, ha. The role model of little girls everywhere.”

“So I should proudly represent the country which brain-washed me, and turned me into a killer?” Natasha questioned bitterly.

Yelena shrugged, and then pointed out, “The Red Room did that, not mother Russia.”

“The Red Room had the full support of the Russian government, regardless of what they claim.” Natasha said softly, taking another sip of her drink, before adding, “And I disagree with some of their policies.”

“Unlike you, I try not to get involved in politics. Unless I’m ordered too.” Yelena shrugged, finishing her drink before admitting, “Although I do see your point. Of course, I didn’t come here to argue about politics.”

“So, why are you here?” Natasha questioned.

“I can’t just visit my sister, and drink her alcohol?” Yelena asked with a teasing smile, and then after a few long seconds of Natasha just looking at her, she looked away and softly admitted, “I have a job offer.”

“To kill me?” Natasha guessed with a raised eyebrow.

“No.” Yelena laughed, then after a few long seconds questioned with obvious hurt in her voice, “Natasha, do you really think I would do that to you?”

“If the last time we saw each other should teach us anything, it’s that in this world, we don’t always have a choice.” Natasha said bitterly, finishing her drink and then pouring herself and the other Widow another.

“Perhaps.” Yelena admitted bitterly, before quickly adding, “But I cannot imagine allowing myself to do that to you.”

“Perhaps you just lack imagination.” Natasha said bitterly, taking a sip of her new drink.

“Could you kill me?” Yelena questioned, taking a sip of the new drink afterwards, afraid of the answer, but having to know it.

“Only if I had too.” Natasha said softly.

There was a brief pause, and then Yelena admitted, “If it was you or me, I’d want it to be you.”

“I wouldn’t…” Natasha said sadly, before asking after another brief pause, “So, what’s this job offer?”

Yelena finished her glass, poured herself another, and then explained, “From what I can tell, it is like SHIELD used to be. Except for the Hydra infiltration. At least, as far as I can tell. After what happened to you, I was careful to research it. It’s called SWORD, because apparently Americans love their ridiculous names. But it seems like an ideal place for us.”

“Us?” Natasha questioned with a raised eyebrow.

“Us.” Yelena confirmed, taking a big sip of her drink as she turned to her ‘sister’ and gave her the ‘hard sell’, “An organization like that is always looking for people with our skill set to do their dirty work. But I’m not naïve. I know things can go south very quickly, which is why I would like someone to watch my back.”

There was a brief pause, and then Natasha asked with a raised eyebrow, “Alexi? Melina?”

“They joined before I did.” Yelena admitted, before pointing out, “But we never truly trusted them. Not when they were pretending to be our parents, and certainly not during our last mission together. No, we need someone we can both truly trust to have our backs. We need each other, as it always should’ve been. Please… Natasha, do not leave me on my own again.”

Yelena’s voice sounded so soft and vulnerable, but Natasha couldn’t afford to trust it, “Are you really trying to try that with a Black Widow?”

“No.” Yelena shook her head, “You’re supposed to be the best of us, so you should know the difference between fact and fiction.”

“Perhaps.” Natasha grumbled, “But you are very good.”

Yelena glared at her sister for a few long seconds, the woman definitely feeling like a sibling in that moment, before she huffed, “Fine. If you won’t do it for me, do it for you. I know you said you were happier in The Avengers, but I truly struggle to see what you add to the team.

Even now they’re fractured, they’re filled with a billionaire, a mind reader, a couple of superhumans, and a God. And if you continue fighting alongside them, you will get hurt. We both know it. It’s only a matter of time before something comes for them, that you will not be able to fight. Everyone knows it, but no one has the guts to say it to your face. No one but me. You need to leave The Avengers, Nat. Even if it isn’t for me. Hell, take the retirement you wanted for me so badly.”

“I can’t do that, and you know it…” Natasha admitted softly.

“So you’re an Avenger, until it kills you?” Yelena questioned in disbelief, and then when there was a telling silence she finished her drink in one go, and grumbled, “Fine, then we do this the hard way.”

With that, Yelena abruptly straddled Natasha and kissed her. It happened so fast that most people wouldn’t be able to counter it, but the most trendy of The Black Widows was not most people. There was a nanosecond where she could have done something, but she was a little taken aback by Yelena’s choice of positions.

Besides, given the previous conversation, she was expecting them to fight, and she was eager to let the other assassin land the first strike, to help get this out of her system. What she could have never anticipated, was for her little sister to kiss her right on the lips. Something which stunned the redhead so much, it was several long seconds, or maybe even a full minute, before she pushed the blonde off of her.

“Yelena! What are you doing!” Natasha exclaimed, before pointing out, “I thought you said we were sisters.”

“I thought you said we weren’t.” Yelena argued, before arguing, and we’re not. At least not by blood. Although personally, I sort of wish we were. It would make things that much more, fun.”

“Oh God.” Natasha whispered softly, but also kinda laughed.

“And you must admit…” Yelena continued, “Constantly trying to protect me, holding me close when we were little, and being the only person who truly loved me, are the sort of things which would give a girl ideas.”

“That wasn’t my intention.” Natasha grumbled.

“I know.” Yelena shrugged, before quickly pointing out, “But is it that surprising I would develop a crush on you? Given everything we went through when we were younger, and how you… developed? God Natasha, it feels like the whole world wants you, and they don’t even know you. But I’ve seen you at your best, and your worst, and I still do.”

There was a brief pause, then Natasha softly said, “That’s… flattering, and weird, but-“

“Love is for children? I know, I know…” Yelena said dismissively, “But I’m not talking about love. I’m talking about sex. Everyone knows that ‘The Black Widow’ loves sex. Just like her… sisters. And just as I know that I wouldn’t be the first blonde girl you’ve fucked. Leading me to the obvious question… when you were with them, were you thinking of me?”

“You wish.” Natasha scoffed.

“Yes, I do.” Yelena smirked, before adding, “Oh, and I’ve never been butt fucked. From what I hear, that might seal the deal for you. That, and the fact I would be happy to bang your big booty in return.”

Natasha stared at her sister for a few long seconds, downed her drink, and then laughed, “You’ve done your research, huh?”

“All the time.” Yelena said, before adding, “Now, where were we. Oh yes, to be clear, this can be a one off, if you want. No strings attached. But, if you follow me to SWORD, we can do this whenever you want. We can do anything you want, while doing it. I can even be your bitch, if you like. Or you can be mine. I don’t care, I just want you by my side, so we can try and protect each other. Just like old times.”

That certainly didn’t sound like a no strings attached offer, but then again, it rarely was when dealing with someone you actually knew. And they could go around, and around, and around arguing they had been drinking, and this was wrong, etc, etc, etc. But honestly? Natasha didn’t care about any of that, and they both knew it, meaning that there was no point in fighting it.

Not when, again if Natasha was honest, this was something that she wanted too. So regardless of how wrong this was, or what consequences it might have, the redhead put the glass down, and then moved cautiously closer to the blonde. Expecting a kiss, or at least hoping for it, Yelena closed her eyes hopefully, only for her ‘sister’ to clarify a few things.

“If we were to do this, it would be a one time thing.” Natasha said firmly.

“Of course.” Yelena beamed, clearly not believing the other woman.

“And you don’t tell anyone. Ever.” Natasha pushed.

“Maybe.” Yelena teased, before rolling her eyes when she got a look from the other Widow, “Okay, yes, fine, whatever.”

“And you do everything I say.” Natasha said softly, cupping Yelena’s cheek in the process.

“God yes…” Yelena eagerly agreed, her eyes darting down to Natasha’s lips.

Yelena had always wanted to feel those lips against her own, and while that first kiss had been fun, she couldn’t truly relax and enjoy it, given that she knew it would end at any second. As a result, the second kiss was far more enjoyable for her, especially as it was her ‘big sister’ who initiated it.

Oh God, the infamous Natasha Romanoff seem to be searching for another reason not to do this for a few long seconds, before giving up, leaning forward, and pressing their lips together. Compared to the first kiss, this was surprisingly gentle, and even sweet. The kind of kiss Yelena liked to imagine Natasha giving her after sex, not before it. Although it was still very much welcomed, as would any kiss from this amazing woman would be.

Not wanting to push her luck, Yelena allowed that second kiss to be long, slow and sweet. She also allowed herself to become so lost in it she almost didn’t notice that they were moving. Almost. But she was aware of it, and, and more importantly, she knew it was a good thing, as they were heading in the direction of Natasha’s bedroom.

They were even removing their clothes along the way, and their own, which was mostly a good thing, as Yelena wanted them to be naked ASAP. But on the other hand, she also wanted to see Natasha Romanoff stripping for her. Oh well, hopefully she would get her chance another time. For now, she was happy with pinning the other Black Widow down, getting on top of her, and grabbing a handful of those legendary tits.

“Wow…” Yelena murmured softly, before grinning evilly, “Oh Wow! Mmmmmmmmm, these are even better than they look. And I didn’t think that was efficient.”

“You like?” Natasha raised an eyebrow.

“Who doesn’t?” Yelena teased, “Mmmmmmmmm yessssssssss, everyone wants a piece of these big tits, sister.”

“Well, you first, sister.” Natasha narrowed her eyes, then grinned as she flipped them over, “Mmmmmmmmm yessssssssssss, you first.”

It was hard to complain about that, considering it involved the infamous Natasha Romanoff grabbing hold of her tits and expertly fondling them, while pressing their lips back together. Especially as that third kiss was exactly what Yelena had always dreamed of. Oh yes, it was hard to imagine how it could be better. Well, she was not allowed to touch Natasha’s tits again.

Hopefully that would change soon, but for now, her hands were pushed away from that area, and the other Black Widow’s equally legendary booty, so the main focus could be on Yelena’s tits. Which felt really good, her ‘sister’ more than living up to her reputation. Hell, for a few moments there, Yelena thought she would cum just from this. Especially when the redhead’s lips moved lower.

There was a little attention to her neck first, but Yelena’s mind was still dazed from the intense kiss with the woman she liked thinking of as her sibling. And she hoped that not only was Natasha marking her as hers, but she would soon get to return the favour. Because it was true, as far as she was concerned. Oh yes, she already belonged to Natasha, and she wanted to make sure that Natasha belonged to her as well. That’s what she wanted.

That’s what she always wanted. And having the infamous Natasha Romanoff sucking on her tits was definitely a positive sign. But as pleasant as it was, Yelena really, really wanted to switch positions, so she could go after those legendary boobs she had always dreamed about.

Natasha would have loved to claim that this was something that came out of left field for her, and that Yelena was completely alone in her unsisterly feelings towards her. Deep down, she expected Yelena might have a tiny crush on her, but she didn’t expect her to try to do something about it. Or that she’d respond like this.

But it’d been a while since Natasha had been able to give into this kind of temptation, and technically, it was a temptation like no other. Oh yes, ‘The Black Widow’ had indulged in all kinds of sexual activity, but to actually fuck her own sister? Or at least, a woman who might as well be her sister? Oh God, that was just too wonderfully wicked to pass up.

Honestly, they hadn’t even started yet, and this was the best sex she’d had in a very, very long while. She certainly couldn’t remember the last time she was this into foreplay. Then again, Yelena’s tits were really underrated. At least compared to hers. Of course, when Yelena flipped them over, Natasha didn’t really fight hard to stop her.

No, she just laid back, and let her ‘sister’ copy everything she had just done to her. Oh yes, Yelena went right for Natasha’s neck, like she was trying to mark her territory, before moving downwards, more or less doing the same thing with her boobs. Although, instead of starting out slow, and working her way up, the blonde latched onto one of the redhead’s nipples, and started sucking it hard right from the start.

She also aggressively flicked her nipples with her tongue, and best of all, dug her teeth into them. Natasha loved that part the best, and Yelena did a commendable job of moving back and forth between those big tits. The little bitch even made sure to give the juicy flesh surrounding the nipples some much-needed attention, first with her lips and then with her hands. Again, just like Natasha had done to her.

Which made the most famous Black Widow wonder whether she had taught her sister something? Probably not how to please a woman, but how to please her? Then again, Yelena probably knew her better than anyone, apart from maybe Clint, so it could be simply a series of educated guesses. But either way, it was very much welcomed.

It didn’t really matter in that moment, of course. No, the main focus of the Black Widows was giving as good as they got, constantly flipping the other over, so they could take over dishing out the boobs worship, as their hands became more bold. Natasha was one to give Yelena the green light on this by doing it first, namely cupping the other girl’s boobs into her mouth, and then grabbing her little sister’s big round ass, much to the delight of both sisters.

Especially as when the roles were reversed, she got to repay the favour. And it might have even emboldened her not to stop the switching of positions next time, but then actually re-positioning herself, so that her pussy was hovering directly over Natasha’s face, AKA, exactly where she wanted her.

“Eat me, sister! Oooooooooooooh yessssssssssssss, eat my pussy.” Yelena moaned tauntingly, her Russian accent thick with lust. Then her eyes went wide and she cried out loudly, “Eat my fucking cunt! Ohhhhhhhhhhhhh yeahhhhhhhhhh, show me exactly what the mighty Natasha Romanoff can do with her tongue! Ooooooooooooooh yessssssssssssss, lick me! Ah fuck! AH FUCK! OOOOOOOOOOOOOOHHHHHHHHHHHHHHH YEEEEEEEEEEEEEEEEEEEESSSSSSSSSSSSSSSSSSSS, MMMMMMMMMMMMM FUCK! FUCK! FUCK ME! OHHHHHHHHHHHHHH YEAHHHHHHHHHHHH! FUCK YES, EAT ME! OH GOD, TONGUE MY FUCKING CUNT YOU BITCH! YEAHHHHHHHHHHHH, FUCK ME JUST LIKE THAT! JUST LIKE THAT! OH FUCK YEAH, AAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHH FUCKKKKKKKKKKKKKKKKKKK!”

Yelena initially intended to get right to eating the other Black Widow’s pussy at the same time she received the same treatment, or maybe even before, but she just couldn’t withstand taunting her undercover sibling. Then the infamous Natasha Romanoff actually stuck out her tongue and started licking her pussy, and Yelena just lost it.

Especially because, again, at times like this it was easy to forget that Natasha wasn’t her sister by blood. Oh yes, in that moment it felt like her big sister really was tonguing her twat, and the combination of that wondered, and the act itself, made it hard to think clearly. Sure, she continued speaking, but she wasn’t really aware of what she was saying, as it was just swear words and sounds of pleasure.

When she did come to her senses, Yelena hated herself for her weakness. After all, it wasn’t like Natasha was even giving her everything she could. Not even close. Sure, occasionally she brushed Yelena’s clit, but mostly, the redhead concentrated on giving the blonde long, slow licks, which completely avoided her most sensitive areas.

Which was ironic, given that Natasha had been initially hesitant to do this. Then again, was she doing this nice and slowly, because she was hoping to receive the same treatment? Probably. And she would. However, the ‘younger sister’ couldn’t withstand the urge to be selfish and wait for it, and thus hopefully annoy the older sister in the process.

Given the expression she could feel against her cunt, Yelena was certain she succeeded, which made this wonderful moment even more satisfying. Which was really, really saying something. Especially given the position they were in. Oh yes, another reason that the far less trendy Black Widow hesitated to return the favour.